


Since We've Been Wrong

by MissKierie



Category: Undertale (Video Game)
Genre: Boys with pussies, Cunnilingus, Ecto-Genitalia (Undertale), M/M, Oral Sex, Other, Porn With Plot, Voyeurism
Language: English
Status: In-Progress
Published: 2019-02-06
Updated: 2019-02-22
Packaged: 2019-10-23 15:41:55
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,186
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17686307
Author URL: https://archiveofourown.org/users/MissKierie/pseuds/MissKierie
Summary: this shouldn't have happened. this shouldn't have worked.your research presented you with a dilemma that you not only didn't expect, but couldn't fathom how to deal with. what do you do when your life's work hands you not results, but a mirror? it tells you to look into your reflection. it says 'this is your answer, sans. it's you.'the universe is either especially cruel or perceptive. either way, you don't like it.





	1. Papyrus makes nachos

**Author's Note:**

> Hello! haha, long time no see : ) if you're still around to read my work, I love and appreciate you more than you can know. Thank you. Thank you.
> 
> This is going to be a short story. Just examining a Sans ship I particularly love. Expect lots of smut and angst. Cuz it's me, lmao, what else would you expect? 
> 
> I will tag things as they occur in the story, to avoid spoilers. With every new chapter, be sure to check the tags to see if anything might be triggering to you. 
> 
> The capitalization (or lack thereof) is deliberate.
> 
> The title is a song by the Mars Volta.
> 
> I love you and hope you will enjoy another story from me.

it’s been thousands of years since the monsters were imprisoned in the underground. you weren’t there to see it happen, but the war and subsequent consequences have left a permanent scar. the pain trickles down the generations, fueled by the lust for revenge and a reunion with the outside world. it’s a double-edged sword, really. it pushes monsters to advance in technology and strength, while filling our mouths with bile. eventually, it will spill out and we’ll be left to stew in our own poison, alone.

in the thirst for advancement, Gaster lost himself. he was gone but not really gone. he fell in the core and died, but he’s still there. there are traces of him, not left behind, rather slipping through the cracks of reality. he can speak to you and sometimes you can even see him out of the corner of your eye. not like a ghost. more like an entangled particle, blipping in and out of existence.

maybe he didn’t fall in the first place. maybe he jumped. and maybe whatever he was trying to do worked. … you really don’t know.

if he’s not there… but is there, then maybe he’s just on another world line. and if more than one world line can exist at once, who’s to say there aren’t more?

you wish the old bastard wasn’t so tight-lipped about his last experiment. you and Papyrus were his assistants. you were close. he always asked for your help and hypotheses. ‘timeline bouncing’ was well known between you three. why then, did he shut himself in during his last few weeks? why didn’t he let you come with him? did he not trust you enough?

it’s hard not to feel bitter about it. he abandoned you, whether it was intentional or not. and you’re left to pick up the pieces he left behind. 

something bad is coming. and you need to get this machine working before it arrives. it’ll have the same abilities as that flower. maybe worse. and you’re going to need a way to reset everything yourself, should it come to that.

you’re hunched over your desk, soldering iron in one hand. a drop of molten copper lands on the tip of your finger, fuck! ouch! that’s hot! you stop yourself from throwing the tool or the motherboard you’re working on away from you. just grit your teeth and keep working. it’s almost time for—

“DINNER!!!” Papyrus’s voice rings from the far wall. “SANS!” he screams while pounding on the wall— he’s on the other side of it, in the living room, “I MADE NACHOS!!!”

hell yeah, nachos. you bring a few strips of wire together on the motherboard as you respond to your brother, “i’ll be right there, bro.” you turn off the soldering iron. you made the mistake of leaving it on once, never again. that’s how you burned down the old half of the laboratory. well, that’s what you tell people at least.

“WHAT???” Papyrus shouts in reply, “I CAN’T HEAR YOU! THERE’S A WALL BETWEEN US!”

“i said,” you teleport into the living room already sitting on the couch, “i’ll be right there, bro.”

Papyrus EEPS in suprise, throwing the full plate of hot nachos in the air. He swiftly follows it with the platter and it lands with a flop, looking less appetizing than it did before. not much less, it looked pretty unappetizing to begin with. “YOU SCARED ME, SANS! I NEARLY LOST MY LUNCH!” you both chuckle at that.

“smells good. what kind of meat’s on it this time?”

“TOFU,” he beams, setting it on the middle cushion as he sits down on the other side of the couch. “I ADDED LOTS OF CAYENNE AND PEPPERS, SO DON’T RUSH YOURSELF.” the burnt tortilla chips are piled high with brown tofu, nacho cheese, jalapeno slices, and salsa. there are a few strands of spaghetti in there too, because why not.

you don’t listen to him, taking a handful of chips and shoving them in your mouth. the capsaicin immediately hits you, your eyes going blank as your face slowly starts to turn red. “suh-sp, uuuh,” you stutter into your hand, “SPICY!!!”

“WHAT DID I TELL YOU?” Papyrus sighs as he takes a chip with 3 jalapeno slices on it and pops it in his mouth.

you run into the kitchen, throwing the refrigerator door open to get the full jug of spider milk. “USE A CUP!” you hear Papyrus remind you from the kitchen. with sweat pooling down your face, teeth clenched, you carefully get a clean cup from the drying rack and pour the milk into it. you throw your head back and down the milk in one gulp. you fill the cup up three more times before burping and heading back into the living room.

“great nachos, bro. i think this is your best work.”

“THANKS! UNDYNE’S LESSONS ARE REALLY PAYING OFF!” Papyrus replies as he turns on the television. MTT is on. he’s playing Twister by himself as a random stage hand spins the wheel. right foot red. Mettaton moves his singular wheel to a red dot on the mat. uproarious applause.

there’s silence between you two while you eat. Papyrus is normally so talkative. you wonder if something happened.

“SANS,” he says, holding a chip halfway to his mouth. a dollop of cheese slowly stretches towards the plate. “DO YOU KEEP SECRETS FROM ME?”

you’re a bit taken back by that. of course you do, but you try to tell him everything important. you aren’t going to tell him every time you get laid or crap like that. “sometimes,” you reply casually, “never anything important, though. i wouldn’t wanna keep my baby brother in the dark. why? is there something you think i’m keeping from you?”

Papyrus sighs and puts the tortilla chip down. he brings his hands together, tapping the tips of his mittens together. “NO… IT’S BECAUSE... I’M KEEPING A SECRET FROM YOU.”

oh, you weren’t expecting that. what could he be hiding? he tells you everything. or so you thought. “is it about your flower friend?” you guess.

“NO,” he says sheepishly, “IT’S A NEW FRIEND I’VE MADE. BUT I DON’T… HE DOESN’T, UM,” he trails off.

you put your hand on his shoulder and give it a squeeze. “that’s okay, paps. you don’t have to tell me. i’m just happy you’re getting out enough to have secrets in the first place.”

“CURSE YOU, SANS!!!” he suddenly screams out, “YOU’RE WINNING AT BEING THE BETTER BROTHER!!! HOW CAN I COMPETE WITH SUCH A THOUGHTFUL RESPONSE?!” he tears up a little bit as he stares at the ceiling.

you snicker and give his shoulder a little punch. “what’re you talking about? you made me dinner. you’re the only thing keeping me in clean clothes and alive.”

Papyrus wipes the tears from his eyes. “YOU’RE RIGHT! I CAN STILL BE THE PERFECT SIBLING! FORGET I SAID ANYTHING.”

yeah right. ’he,’ huh? now you’re curious.

the two of you have dinner in relative silence. the tv fills the dead air. you thank him and return to your work.

you don’t know what blew the first motherboard. you guess it doesn’t matter now. the new board looks like it’s connected correctly. you take your time checking every fuse and wire. every dial. every transistor. you don’t want anything to short circuit. computer parts aren’t exactly readily available.

you take a deep breath and stare at the ON switch. with a shaking hand, you reach forward and flip it.

darkness.


	2. In a Racecar Bed

**Summary for the Chapter:**

> Papyrus has a car bed with purple covers.

**Notes for the Chapter:**

> sorry it took so long to release this chapter -w- thar be smut, so beware.

THE HOUSE IS QUIET, BUT IT STILL SMELLS LIKE TACO SEASONING DOWNSTAIRS. THE BOMBASTIC HARMONICS OF “SMOOTH HUMAN JAZZ” COMING FROM YOUR COMPUTER IS THE ONLY SOUND IN THE HOUSE.

SANS IS IN HIS ROOM, BUT YOU WISH HE’D BE NOISY!!! THE ONE TIME THAT WOULD BE PERFECT FOR HIM TO PRACTICE HIS TROMBONE AND THE LAZYBONES DOESN’T!

YOUR FRIEND CAME MUCH EARLIER THAN YOU ANTICIPATED. HE WAS ALREADY IN YOUR ROOM BY THE TIME YOU FINISHED DOING THE DISHES. NOT ONLY WAS HE AMAZINGLY SNEAKY, HE ALSO MANAGED TO WORDLESSLY GET YOU ON YOUR PANTS OFF. HE’S GOT YOU LIKE A HELPLESS TURTLE, COMPLETELY IMMOBILIZED ON YOUR BACK ON THE BED. 

HE’S JUST SO… PERSUASIVE! EVEN IF YOU WANTED TO, HOW COULD YOU SAY NO? HE KNOWS YOU BETTED THAN ANYONE!

WHAT A PREDICAMENT! YOU HAVE TO COVER YOUR MOUTH WITH YOUR HAND TO KEEP YOURSELF SILENT AS HE DUCKS HIS HEAD BETWEEN YOUR LEGS. YOUR MAGIC IS CENTRALIZING BENEATH YOUR PUBIC ARCH. YOU AREN’T SURE WHICH PARTS WILL FORM THIS TIME… YOU’RE STILL GETTING THE HANG OF THIS.

THANKFULLY, YOUR NEW FRIEND IS SO PATIENT! HIS TONGUE PLAYS WITH YOUR OBTURATOR FORAMEN, THRUSTING INTO THE SMALL HOLES AND OH, OH YOU LIKE THAT! 

THE COVERS ARE OVER HIM, WHICH MAKES WHAT HE’S DOING ALL THE MORE EXCITING! YOU CAN FEEL HOS HOT BREATH ON YOU. OOH, YOU MUST HAVE MADE A CUMMY, YOU CAN FEEL HIM KISS YOUR LABIA BEFORE SLIDING HIS TONGUE UP THE ENTIRE LENGTH. 

IT FEELS GOOD!!! IT FEELS SO GOOD! YOU CAN’T BELIEVE HOW WET YOU ARE. MAYBE YOU DO LIKE SNEAKING AROUND?? AND LYING? OH, PAPYRUS, WHAT HAVE YOU BECOME?!?

HIS TONGUE PUSHES INSIDE AND PAST THE ROWS OF TEXTURED MAGIC TO FLICK AT THE MOST DEEPEST PART OF YOU. YOU CAN’T HELP BUT MAKE A SMALL NOISE OF PLEASURE, YOUR PHALANGES GRIPPING TIGTHER OVER YOUR TEETH.. HE’S GRUMBLING UNDER THE BLANKET— YOU CAN FEEL THE VIBRATION IN YOUR PELVIS.

“GOOD BOY,” YOU HEAR HIM MUMBLE AND IT MAKES YOUR MAGIC THROB. 

YOU SPREAD YOUR LEGS WIDER AND HE PUSHES A FINGER INSIDE. IT FEELS SO THICK, BUT IT’S SO NICE TO BE SO FULL! HE’S LAPPING AT YOUR CLIT, AHH, AH! YOU CLOSE STARE UP AT THE CEILING, NOISY SAXOPHONE FILLING IN THE QUIET SPACE. THE PACE OF THE MUSIC EXCITES YOU EVEN MORE AND YOU REACH DOWN TO REST YOUR HAND ON HIS HEAD. HE’S SO WARM.

“ONE MORE,” HE WHISPERS, BEFORE SLIDING ANOTHER FINGER BETWEEN YOUR FOLDS. IT’S SO MUCH! THE LARGEST THING YOU’VE EVER HAD INSIDE YOU! HE’S THRUSTING THEM AND OH TO THE STARS ABOVE, YOU FEEL LIKE YOU’RE GOING TO BURST!!!

YOUR CELL PHONE BUZZES ON THE END TABLE. IT MIGHT BE UNDYNE CALLING TO OFFER YOU A FORMAL SPOT IN THE ROYAL GUARD, YOU HAVE TO TAKE IT! WITH YOUR FREE HAND, YOU GRAB IT, AND IT IMMEDIATELY STOPS BUZZING. OH, IT’S A TEXT, FROM SANS!

SANS, DEAR BROTHER✨❤️: hey bro. i’m sorry, but i lies to you earlier. i do have a secret.

YOUR FRIEND IS STILL LAPPING AT YOUR CLIT, HE’S RUMBLING HAPPY SOUNDS INTO YOUR BODY. HIS FINGERS CURL UP AND START PULLING INTO THAT DELICIOUS SPOT INSIDE. THAT STRANGE FEELING IS COMING BACK, THE FEELING THAT YOU WANT TO EXPLODE!!!

YOU SWALLOW HARD AND BRING YOUR OTHER HAND UP TO REPLY TO YOUR BROTHER. YOU CAN’T LEAVE HIM HANGING.

THE GREAT PAPYRUS!: OH REALLY???

SANS, DEAR BROTHER✨❤️: i started working on the machine again.

THAT WOULD NORMALLY UPSET YOU— THAT MACHINE PROVED FRUITLESS OVER AND OVER AND YOUR BROTHER WAS OBSESSED WITH IT. HE STOPPED EATING, NAPPING. HE WASN’T HIMSELF. 

BUT INSTEAD YOU FEEL GUILTY. 

THE GREAT PAPYRUS!: WHY DIDN’T YOU TELL ME?

SANS, DEAR BROTHER✨❤️: cuz i knew you’d tell me to stop. but i can’t. and i think i can get it to work this time. i dunno, i’ve just got a bad feeling. i think we’ll need it.

YOUR FRIEND SITS UP, BUT HE’S STILL GOT THE SHEETS OVER HIS HEAD. ALL YOU CAN SEE ARE HIS GLOWING EYES. HE SILENTLY RUBS THE HEAD OF HIS COCK AGAINST THE FINGERS STILL INSIDE YOU. HE’S ASKING IF YOU’RE READY.

YOU WANT IT, YOU WANT TO FEEL SO FULL, TO FEEL HIM COMPLETE YOU, TO FEEL HIS WARMTH. 

BUT YOU AREN’T READY. THIS ISN’T NEARLY ROMANTIC ENOUGH TO LOSE YOUR VIRGINITY! 

YOU JUST LOOK AT HIM LONGINGLY BEFORE SHAKING YOUR HEAD. NOT YET.

HE SUDDENLY SPRINGS FORWARD AND LIES ON TOP OF YOU!!! HIS FINGERS START MOVING SO FAST! HE’S SO HEAVY! HE PRESSES HIS MOUTH TO YOURS AND YOU SQUIRT INTO HIS WAITING HAND.

“NYEH!!!” YOU CAN’T HELP BUT CRY OUT AS YOUR BODY ‘BREAKS THE DAM,’ SO MUCH BUILT UP ENERGY AND NEED SPILLING OUT OF YOU AS HIS FINGERS CONTINUE THRUSTING.

THE SOUND OF HIS HAND SLAPPING AGAINST YOUR SOPPING WET PUSSY IS NOISY AND WITH A SHAKY GRIP, YOU ASK YOUR FRIEND TO STOP. HE DOES.

SANS MUST HAVE HEARD THAT!!! OH DEAR, HE SENT YOU A TEXT! 

SANS, DEAR BROTHER✨❤️: are you mad?

YOUR FRIEND GIVES YOU ANOTHER KISS BEFORE SLIDING BACK BETWEEN YOU’RE LEGS. OH, SO IT’S ONE OF THESE NIGHTS, IS IT??? YOU WILL PROVE TO HIM YOU HAVE MORE SEXUAL STAMINA FOR SURE THIS TIME!!

THE GREAT PAPYRUS!: OF COURSE NOT, BROTHER! I LOVE YOU AND WANT TO SUPPORT YOU! I ACTUALLY THINK YOUR UPGRADES WILL WORK THIS TIME ;)

YOU REALIZE THE WINKY FACE MIGHT’VE BEEN A BAD IDEA, OOPS! 

SANS, DEAR BROTHER✨❤️: thanks. i love you too, bro.

**Notes for the Chapter:**

> sorry for all the capitalization T_T


End file.
